In the past various types of spray nozzles have been employed for high pressure aqueous slurries to provide a spray for one or more purposes. Such a use is typified in spraying limestone slurry in a tower, stack or chamber where it is contacted by combustion gases from the burning of coal. The limestone reacts with sulfurous gases such as sulfur dioxide and the like to form calcium sulfate which is separated from the thus scrubbed gases.
Typical of such spray nozzles is one made of stainless steel with internal vanes to impart a swirling motion to the high pressure slurry to enhance the formation of the spray through which the combustion gas or smoke from the burning of coal is passed. Such nozzles while initially strong and durable are subject over a period of time to pitting and corrosion on the surfaces contacted by the slurry and wear which greatly shortens their life. The rigidity of the vanes further causes problems in occasional clogging of the vanes. All of this contributes to downtime and the attendant expense and reduced efficiency necessitated by repairs and replacement.
Ceramic spray nozzles have likewise been employed in such sustems. While they exhibit improved corrosion and pitting resistance they are relatively fragile and have lessened shock resistance and are subject to breakage. Due to their rigidity they further experience objectionable clogging tendencies to larger sizes of slurry solids. Their increased expense adds to problems in their advantageous employment.